Automatic gyration control means for centrifugal extractors



Feb. 13, 1934. N. R. ANDREWS Er AL 1,946,725

AUTOMATIC GYRATION CONTROL MEANS FOR CENTRIFUGAL EXTRACTORS Filed June-l, 1932 4- Sheets-Sheet l .4T ORNEY Feb. 13, 1934. N W r AL 1,946,725

AUTOMATIC GYRATION CONTROL MEANS FOR CENTRIFUGAL EXTRACTORS Filed June1, 1932 4 Sheets-Sheet 2 INVENTORS JKJZ flrzafi'ews and B YJ:

Feb. 13, 1934. N, R: ANDREWS El AL 1,946,725

AUTOMATIC GYRATION CONTROL MEANS FOR CENTRIF UGAL EXTRACTORS Filed June1, 1932 4 Sheets-Sheet 3 I v I l 1 l JTTOL'NEY 1934- N. R. ANDREWS ET ALAUTOMATIC GYRATION CONTROL MEANS FOR CENTRIFUGAL EXTRACTORS Filed June1, 1952 4 Sheets-Sheet 4 IN VEN TORS BY 7.1m,

ATT RNEY Patented Feb. 13, 1934 PATENT OFFICE AUTOMATIC GYRATION CONTROLMEANS FOR CENTRIFUGAL EXTRACTORS Nathaniel R. Andrews; Yonkers, andJacob J. Neuman, New York, N. Y.

Application June 1, 1932. Serial No. 614,726

11 Claims. (Cl. 210-72) This invention relates to automatic gyrationcontrol means for centrifugal extractors, and has for its primary objectand purpose to provide an automatically operated switch for controllingthe accelerating and decelerating circuits, or the clutch and brakegoverning the operation of the centrifugal basket whereby, in the eventof uneven loading of the basket, the destructive gyratory motionincident thereto will be speedily corrected, and without appreciableinterruption in the continuous operation of the machine.

It is a more particular object of the inven tion to provide such anautomatic gyration controi means particularly designed for applicationand use in connection with sugar refining centrifugals, and which is soconstructed, that the automatic charging of the centrifugal basket mayalso be thereby controlled in the event that such gyratory motion of thebasket should occur during the charging operation.

It is another important object of the invention to provide meansembodying an automatically actuated switch for opening and closing thedecelerating and accelerating circuits and which includes means operableafter the decelerating circuit has been closed to delay or retard movement of the switch to a position whereby the accelerating circuit isclosed, and thus afford ampie time for gyratory motion of the basket tocease before the said basket is again rotated at maximum speed.

With the above and other. objects in view, the invention consists in theimproved automatic gyration control means for centrifugal machines, andin the form, construction andrelative arrangements of its several partsas will be hereinafter more fully described, illustrated in theaccompanying drawings and subsequently incorporated in the subjoinedclaims.

In the drawings wherein we have disclosed one simple and practicalembodiment of our present invention, and in which similar referencecharacters designate corresponding parts throughout the several views,-

Figure 1 is a vertical sectional view showing a centrifugal extractor ofmore or less conventional form having our improved automatic gyrationcontrol device mounted upon the basket casing or housing;

Fig. 2 is a top plan view thereof;

Fig. 3 is a diagrammatic plan view illustrating the operation of theswitch actuating arm upon gyratory movement of the centrifugal basket;

Fig. 4 is a vertical longitudinal sectional view through the controldevice;

Fig. 5 is a top plan View of said device with the cover of the housingremoved and certain parts broken away and shown in section; and

Fig. 6 is a transverse sectional view showing the oscillatory mercuryswitch in normal position for the high speed operation of thecentrifugal basket.

In Figs. 1 and 2 of the drawings, we have shown a well-known type ofcentrifugal extractor such as is used in refining sugar, and in whichthe rotating basket 5 is enclosed within an outer housing 6 provided atits upper end with an inwardly extending annular curb or flange 7. The

basket 5 is also provided at the upper end thereof with an inwardlyextending annular rim 8. Within the basket to rotate as a unittherewith, the usual distributor plate 9 is arranged whereby the rawsugar falling by gravity upon said plate is centrifugally distributedand walled up against the cylindrical wall of the basket 5 in the mannerindicated in Fig. 1 of the drawings.

Upon the curb '7 of the basket housing 6, there is suitably mounted orsecured a casing 10 enclosing the principal movable elements of thecontrol device. This casing at one of its ends has 2. depending tubularpart 11 disposed beyond the edge of the curb 7 and extending within thehousing 6. In this depending part 11 of the casing, a verticallydisposed shaft 12 is mounted in the spaced bearings 13. This shaft atits lower end has a reduced threaded extension 14 to which the upper endof the spindle 15 is detachably connected. The lower end of this spindleis formed with the bearing flange 16 for the collar 18 on one end of aradially disposed arm 17. In longitudinally spaced relation from thecollar 18, a second collar 19 is fixed upon the spindle 15. The upperend of a coil spring 20 is suitably attached to the collar 19, while theother or lower end thereof is attached to the collar 18.

Upon the upper end of the shaft 12 within the casing 10, a gear 21 isfixed and is in constant mesh with a pinion 22, secured upon thehorizontally disposed shaft 23 journalled in the spaced bearings 24.

Upon one end of the shaft 23, and. extending at right angles to the axisthereof, a bar 25 is centrally fixed. The opposite ends of this bar areadapted for engagement with the spaced lugs 26 on one end wall of thecasing 10 to thereby limit the oscillatory motion of the shaft 23 ineach direction.

Upon the shaft 23 between pinion 22 and the bar 25, a radially disposedupwardly projecting arm 27 is fixed. On one side of this arm at itsupper end, a mercury switch tube 28 is suitably mounted. Within thistube at one end thereof, the spaced circuit closing terminals 29 and 30respectively are arranged, the terminal 30 being connected by wire 31with the coil of a relay or other type of switch arranged in the motoraccelerating circuit, or with a solenoid for operating a driving clutch,while the other terminal 29 is connected by wire 32 to the current feedline of the circuit. The switch 28 also has a third terminal 33centrally arranged therein and connected by wire 34 with the coil of therelay or other type of switch controlling the decelerating circuit ofthe operating motor. Insofar as our present invention is concerned, itis not believed to be necessary to further illustrate the acceleratingand decelerating circuits. An example of one arrangement of circuits inwhich the present invention might be connected, is disclosed in ReissuePatent No. 17,378 issued to us on July 23, 1929. If the centrifugalmachine is equipped with automatic charging means, such for instance asthat disclosed in our co-pending application for patent Serial No.399,900, filed October 16, 1929, a second mercury switch tube 35 mayalso be mounted upon the arm 27 and provided with a simflar arrangementof spaced terminals in one end of said tube for effecting movement ofthe charging gate to closed position, in the event that gyratory motionof the centrifugal basket should occur during the charging operation.

To one end of the bar 25, a coil spring 36 is attached at one of itsends, the other end of said spring being suitably attached to the endwall of the casing 10. This spring operates to return the mercury switchtubes to a normal position, as seen in Fig. 6 of the drawings, andwherein the accelerating circuit of the operating motor is closed bycontact of the globule of mercury with the spaced switch terminals 29and 30.

At the other end of the shaft 23, a yoke member 37 is fixed thereto. Thearms of this yoke member straddle a vertically disposed cylinder 38fixed to the bottom wall of the casing 10. This cylinder, together withthe valved piston operating therein within a body of oil or otherliquid, constitutes a dashpot retarding the return movement of themercury switch to normal accelerating position under the action of thespring 36. While this dashpot might be of various approved forms andoperatively connected in any desired manner with the shaft 23, we haveherein shown the rod 39 centrally connected at its lower end to theannular piston 40, and extending through a guide boss on the upper endhead of the cylinder 38. Below this cylinder head, a horizontal rod 41is centrally connected to the piston rod 39 and is movable at itsopposite ends in the vertical slots 42 provided in the wall of thecylinder 38. To said ends of the rod 41, the upper ends of the links 43are pivotally connected, the lower ends of said links being pivotallyattached to the arms of the yoke 37.

The dashpot piston 40 is provided with a suitably formed seat againstwhich the valve disc 44 is yieldably held by the coil spring 45surrounding the piston rod 39 to thereby normally prevent the upwardflow of the liquid through said annular piston, and yieldably resistingsuch flow of the fluid in the downward movement of the piston. In theupward movement of the piston, said valve is closely held upon its seatso that the fluid may flow only between the periphcry of the piston andthe wall of the cylinder 38.

Having above described the several structural features of our presentinvention, its operation will be understood as follows:---

In mounting the device upon the curb of the basket housing, the arm 17is adjusted and arranged so that normally there is a slight clearancebetween the free end of this arm and the edge of the basket rim 8. Inthe event of an unbalanced distribution of the sugar charge against thewall of the basket, there will result a gyratory motion of the basket,and the rim 8 thereof rotating off its true center will press inwardlyagainst the free end of the arm 17. The spring 20 is of such tensionthat shaft 12 and gear 21 rotate as a unit with arm 1'7, thus rocking oroscillating the shaft 23 in one direction and moving the mercury switch28 to the dotted line position shown in Fig. 6 of the drawings. Theglobule of mercury in the switch tube thus moves out of contact withterminals 28 and 29, breaking the accelerating circuit, and in itsmovement into the other end of the tube, establishing a circuitconnection between terminals 29 and 33 to close the deceleratingcircuit, or to operate the brake. In this oscillation of shaft 23, thedashpot piston moves downwardly, valve 44 being unseated so as to permitof the substantially free or unchecked downward movement of the piston.In this manner, the driving motor is slowed down, or if the machine isdriven by a clutch, the clutch is released and the brake applied, thusaffording an opportunity for the fillmass to readjust itself in thebasket, whereupon the gyrating motion of the basket ceases. Pressure ofthe basket rim against arm 17 being thereby relieved, spring 36contracts to return the parts to normal position. The dashpot abovedescribed will effectually prevent continuous contact of the arm 17against the rim of the basket as the gyratory motion of the lattergradually decreases, thereby obviating a back and forth motion of thisarm. This dashpot also retards the re-closing of the motor acceleratingcircuit, after the decelerating circuit is closed, and thereby providesfor ample opportunity for the com plete cessation of gyratory motion ofthe basket before the latter is again rotated at maximum operatingspeed.

In the event of a sudden excessive gyratory motion of the basket tendingto move the arm 1'7 beyond the position necessary to actuate the switchto its decelerating position, the spring 20 yieldingly permits of arotation of this arm on the lower end of the spindle 15, and thusobviates damage or injury to the parts of the mechanism.

From the foregoing description considered in connection with theaccompanying drawings, the construction, manner of operation and severaladvantages of our invention as herein disclosed will be clearly andfully understood. It will be evident that we have provided a very simpleand practical device for the effective automatic control of gyratorymotion of the basket of a centrifugal extractor. Such a device willoperate in a reliable and efficient manner for the intended purpose toquickly cause the complete subsidence of such gyration of the basket andrestore rotation of the latter about its true axial center so thatcontinuous productive operation of such centrifugal extractors will notbe appreciably interrupted. We have herein referred to the use of amercury switch for the control of the accelerating and deceleratingcircuits or the clutch and brake means of the centrifugal drive.

It is, however, more or less evident that other types of switches mightbe substituted to function in substantially the same manner as abovedescribed. Accordingly, it is to be understood that although we haveherein disclosed one practical and satisfactory embodiment of thedevice, the same is nevertheless susceptible of exemplification invarious other alternative structural forms, and we accordingly reservethe privilege of resorting to all such legitimate changes therein as maybe fairly embodied within the spirit and scope of the invention asclaimed.

We claim: I

1. Gyration control means for centrifugal extractors, including movablemeans controlling the transmission of power to the centrifugal basket,means acting to move said movable means to a normal position, and meansoperatively connected with said movable means having a member engagedand actuated by a part connected with the basket upon gyratory motion ofthe latter, to shift said movable means from its normal position, saidnormal position corresponding to one rotary speed of the basket and theshifted position corresponding to another rotary speed of the basket.

2. Gyration control means for centrifugal extractors, including movablemeans controlling the transmission of power to the centrifugal basket,means acting to move said movable means to a normal position, meansoperatively connected with said movable means having a member engagedand actuated by a part connected with the basket upon gyratory motion ofthe latter, to shift said movable means from its normal position, andmeans for retarding the return of said movable means to its normalposition, said normal position corresponding to one rotary speed of thebasket and said shifted position corresponding to another rotary speedof the basket.

3. Gyration control means for centrifugal extractors, including movablemeans controlling the transmission cf power to the centrifugal basket,means acting to move said movable means to a normal position, meansoperatively connected with said movable means having a member en gagedand actuated by a part connected with the basket upon gyratory motion ofthe latter, to shift said movable means from its normal position, and adashpot connected with said movable means and operable to retard itsreturn to normal position, said normal position corresponding to onerotary speed of the basket and said shifted position corresponding toanother rotary speed of the basket.

4. Gyration control means for centrifugal extractors, includingoscillatably mounted means for controlling the transmission of power tothe centrifugal basket, means for oscillating said power transmissioncontrol means in one direction and yieldingly holding the same in anormal position and means for oscillating said control means in theopposite direction having a member engaged and actuated by a partconnected with the basket upon gyratory motion of the latter said normalposition corresponding to one rotary speed of the basket and saidshifted position corresponding to another rotary speed of the besket.

5. Gyration control means for centrifugal extractors, includingoscillatably mounted means for controlling the transmission of power tothe centrifugal basket, means for oscillating said power transmissioncontrol means in one direction and yieldingly holding the same in anormal position, means for oscillating said control means in theopposite direction having a member engaged and actuated by a partconnected with the basket upon gyratory motion of the latter, saidnormal position corresponding to one rotary speed of the basket and saidshifted position corresponding to another rotary speed of the basket.

6. Gyration control means for centrifugal extractors, includingoscillatably mounted means for controlling the transmission of power tothe centrifugal basket, means for oscillating said power transmissioncontrol means in one direction and yieldingly holding the same in anormal position, means for oscillating said control means in theopposite direction having a member engaged and actuated by a partconnected with the basket upon gyratory motion of the latter, and adashpot connected with said operating means and acting to retard thereturn oscillatory movement of said control means to its normalposition, said normal position corresponding to one rotary speed of thebasket and said shifted position corresponding to another rotary speedof the basket.

7. Gyration control means for a centrifugal extractor having a motordriven basket, a motor therefor and accelerating and deceleratingcircuits for the motor, comprising movable switch means for opening andclosing said accelerating and decelerating circuits for the motor, andmeans including a member engaged and operated by a part connected withthe basket upon the development of gyratory motion to actuate saidswitch means and open the accelerating circuit and close thedecelerating circuit of the motor to thereby reduce the rotary speed ofthe basket.

8. Gyration control means for a centrifugal extractor having a motordriven basket, a motor therefor and accelerating and deceleratingcircuits for the motor, said means including an oscillatable switch toopen and close said accelerating and decelerating circuits for themotor, means to oscillate said switch in one direction and yieldinglyhold the same in a normal position closing the motor acceleratingcircuit, and means embodying a member engaged and operated by a partconnected with the basket upon gyratory motion of the latter tooscillate said switch in the opposite direction and thereby open theaccelerating circuit and close the decelerating circuit of the motor toreduce the rotary speed of the basket.

9. Gyration control means for a centrifugal extractor having a motordriven basket, a motor therefor and accelerating and deceleratingcircuits for the motor, said means including an oscillatable switch toopen and close said accelerating and decelerating circuits for themotor, means to oscillate said switch in one direction and yieldinglyhold the same in a normal position closing the accelerating motorcircuit, means embodying a member engaged and operated by a partconnected with the basket upon gyratory motion of the latter tooscillate said switch in the opposite direction and thereby open theaccelerating circuit and close the decelerating circuit of the motor toreduce the rotary speed of the basket, and a dashpot connected with apart of said switch operat ing means to retard the return oscillatingmovement of the switch to normal position and the reclosing of the motoraccelerating circuit.

10. In a centrifugal extractor having a rotary charge receiving basket,and a motor, the combination of movable means for controlling thetransmission of power from said motor to said basket, additional meansmovable as a unit with said first named means, means acting to move bothof said means to a normal position, and means operatively connected withsaid unitary control means having a member engaged and actuated by apart connected with the basket upon gyratory motion of the latter tomove said control means irom its normal position to thereby de-' creasethe rotary speed 0! the basket, and stop or prevent the charging of thebasket.

11. In a centrifugal extractor having a rotary charge receiving basket,and a motor, the combination of movable means for controlling thetransmission of power from said motor to said basket, and supply meansfor charging the basket mal position.

NATHANIEL R. ANDREWS. JACOB J. NEUMAN.

